A combination of thin-layer chromatography and gas–liquid chromatography was used for the separation and determination of fecal bile acids in three middle-aged men during the last 4 days of three 8-day periods on a fat-free diet. The range of the total output was 130–650 mg/day. Lithocholic and deoxycholic acids were the major components and accounted for 65–80% of the total excretion of bile acids. Other common bile acids were present in considerably smaller quantities (0.5–11% each). In addition, evidence was obtained for the presence of a number of as yet unreported fecal bile acids. These were tentatively identified as 3α,12β-dihydroxy-, 3β,12β-dihydroxy-, 3α,7β-dihydroxy-, 3α-monohydroxy-7-keto-, 12α-monohydroxy-3-keto-, and 7β-monohydroxy-cholanic and cholanic acids. The latter three acids occurred in traces only, but the other uncommon fecal bile acids each accounted for 0.5–7% of the total excretion of bile acids. Significant variations were found in the concentrations of several of the bile acids both between different samples from the same subject and between samples from different subjects.
Determination of clofibrate in biological fluids by thin-layer and gas—liquid chromatography